var jsonStr = null;
jsonStr = "{\"deviceId\":\"00000000-4df8-d963-3b64-93f651a1e20a\", \"pushToken\":\"7ee4bfe5-f56a-4685-b594-b443d231236f\", \"userName\":\"guest\"}";
console.log(jsonStr);
jsonStr = eval("(" + jsonStr + ")");
console.log(jsonStr.userName + jsonStr.deviceId + '_pushToken');